I'm not arguing with you, my reply was an insight to my driving conditions here in the US where it gets cold as well. Although it's not anywhere near freezing, I'd like to have the peace of mind that my car can sustain driving in those conditions if needed be. This is the same when I go to the desert, I'd like to know it'll handle the extreme heat and cold. Have you ever been to the desert at night? It gets really cold, but come morning the temperatures soar. Those extremes place an increased demand on the system. Back there maybe not so much as the temps remain consistent around the mid-30's, but here it's entirely different.

In that stovetop experiment, I'm sure with a properly closed system the radiator cap would still increase the boiling point much further. There was a reason that 50/50 anti-freeze and water is the recommended cooling fluid for our system, and that is to get the best of both properties.

To each his own.

Quote Originally Posted by youngrider View Post
IMO, it is really exxpected to have the graphs this way, pure water has:


1. higher heat capacity - volume per volume H2o hold a lot more heat. A smaller capacity cooling sytem with pure water can absorb more heat faster..

2. And_ it has also higher thermal conductivity - Pure water gives up more heat with lesser temperature gradient. In a relatively cooler radiator environment pure water will release more heat faster.

3. Plus_ Pure water has lower viscosity - it will move faster in the cooling system.


....SO PURE WATER HAS A HIGHER HEAT TRANSFER ABILITY....


But is pure water the best coolant for engines, lets take the major CONS:


1. Pure water has a lower freezing point(0C or 32F) - Freezing is not a problem in the Philippines.

2. Pure water has a lower boiling point(100C or 212F). - Most cars today has a normal operating range between 195F to 212F with the Thermovalve fully opening at around 195F. Using a radiator cap with at least 0.9 rating (that is 0.9 x 1 bar or about 14.7 PSI) will raise the boiling point of pure water to 250F or 120C.

There is 3F increase in boiling pt. per one PSI pressure applied. Mixing it with 'coolants also raises its BP. But as said, you really don't want your coolant temperature go beyond 212F coz' the engine metal temperature is much higher than the coolant temperature. The risk for a TOASTED ENGINE is looming.

3. Pure water has a higher surface tension - this translates to a lesser percent coverage per surface area of the cooling system. Redline's water wetter and other SURFACTANTS claim to solve this.

4. With Pure water corrosion is high. Ethylene glycol in pure form is also highly corrosive.

Redline has enlightening technical info and figures, it is good to read their primer on their water wetter product.

http://www.redlineoil.com/whitePaper/17.pdf

Anti-freeze, anti-boil, and anti-corossion properties need not be sourced solely from Glycol products, they can be bought separatety according to your needs and fancies.

The older vehicles operate in a lower operating range, but with the attempt to produce more power per engine displacement, very high fuel economy, and very strict emmision control the results are the high heat producing engines in our time. Diesel engine manufacturers in the US, as diesel are gaining popularity, are predicting a 30% hotter diesel engines in order to comply with the government's regulations on pollution control.

Solution, 50/50 glycol coolant mix?....................